The present invention relates to flight instruments in general, and particularly to standby flight instruments which display essential navigation information in the event of a primary system failure.
The increasing complexity of both commercial and military aircraft systems has been paralleled by multiplication of flight instruments and cockpit displays. In large aircraft especially, navigational information from radar sensors, gyroscopic sensors, etc. frequently undergoes substantial processing before reaching the cockpit display. Furthermore, the interrelation of various aircraft information processing, power supply, and other electrical subsystems increases the likelihood that a failure in one subsystem could leave a pilot deprived of essential airplane attitude and navigational information. A crucial failure in a flight computer could conceivably disable the entire cockpit display.
The prior art is replete with aircraft displays emphasizing various advantages. U.S. Pat. Nos. 3,112,644 and 3,206,974, issued to E. H. Schroeder and Andresen respectively, disclose integrated flight instrument systems having error correcting capabilities based on duplicate pilot/copilot instrumentation. U.S. Pat. Nos. 4,163,387 and 4,340,936, issued to R. L. Schroeder and Mounce, respectively, show microprocessor driven displays for systems of remote sensors. U.S. Pat. No. 4,283,705, issued to James et al teaches the combination on a single display of all necessary flight parameters for controlling flight path during enroute navigation and final instrument approach.
None of the aforementioned systems, however, addresses the problem of instrument loss in the event of a total or partial electric power failure, a communication break to a sensor remote from the display, or a malfunction in the flight computer or other intermediary display processing equipment.